Storage-protein regulation and lipid accumulation in microspore embryos of Brassica napus L.

Taylor, David C.; Weber, Nikolaus; Underhill, E. W.; Pomeroy, M. Keith; Keller, W. A.; Scowcroft, W. R.; Wilen, Ronald W.; Moloney, Maurice M.; Holbrook, Larry A.

doi:10.1007/bf00202320

Cited by 97 publications

(63 citation statements)

References 44 publications

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“…In B. napus it has been shown that exogenous ABA treatment can have profound effects on the accumulation of transcripts and gene products of the major seed storage proteins (9), lipid profiles (8), and on levels of oil-body associated proteins (20). Many ofthe responses stimulated by ABA are also affected by water stress or elevated osmotica (7,8).…”

Section: Introductionmentioning

confidence: 99%

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Effects of Abscisic Acid and High Osmoticum on Storage Protein Gene Expression in Microspore Embryos of Brassica napus

Wilen

Mandel²,

Pharis³

et al. 1990

Plant Physiol.

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Storage protein gene expression, characteristic of mid-to late embryogenesis, was investigated in microspore embryos of rapeseed (Brassica napus). These embryos, derived from the immature male gametophyte, accumulate little or no detectable napin or cruciferin mRNA when cultured on hormone-free medium containing 13% sucrose. The addition of abscisic acid (ABA) to the medium results in an increase in detectable transcripts encoding both these polypeptides. Storage protein mRNA is induced at 1 micromolar ABA with maximum stimulation occurring between 5 and 50 micromolar. This hormone induction results in a level of storage protein mRNA that is comparable to that observed in zygotic embryos of an equivalent morphological stage. Effects similar to that of ABA are noted when 12.5% sorbitol is added to the microspore embryo medium (osmotic potential = 25.5 bars). Time course experiments, to study the induction of napin and cruciferin gene expression demonstrated that the ABA effect occurred much more rapidly than the high osmoticum effect, although after 48 hours, the levels of napin or cruciferin mRNA detected were similar in both treatments. This difference in the rates of induction is consistent with the idea that the osmotic effect may be mediated by ABA which is synthesized in response to the reduced water potential. Measurements of ABA (by gas chromatography-mass spectrometry using [2H6]ABA as an internal standard) present in microspore embryos during sorbitol treatment and in embryos treated with 10 micromolar ABA were performed to investigate this possibility. Within 2 hours of culture on high osmoticum the level of ABA increased substantially and significantly above control and reached a maximum concentration within 24 hours. This elevated concentration was maintained for 48 hours after culturing and represents a sixfold increase over control embryos. The ABA-treated embryos accumulated the hormone very quickly, but ABA concentrations retumed to basal levels within 72 hours after treatment. The possibility that embryosynthesized ABA may be a mediator of effects of osmotic stress on gene expression in Brassica embryos is discussed.several studies on the regulation of gene expression in developing seeds (9, 10). In B. napus it has been shown that exogenous ABA treatment can have profound effects on the accumulation of transcripts and gene products of the major seed storage proteins (9), lipid profiles (8), and on levels of oil-body associated proteins (20). Many ofthe responses stimulated by ABA are also affected by water stress or elevated osmotica (7,8).The relationship between ABA effects and osmotic effects in developing seeds is not yet clear and has yielded results with contrasting interpretations (23). Bray and Beachy (2) suggested that the accumulation of soybean storage proteins, which is enhanced by culturing soybean embryos on high osmotica, is a consequence of elevated ABA content. In B. napus, on the other hand, Finkelstein and Crouch (7)

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Section: Introductionmentioning

confidence: 99%

“…Bray and Beachy (2) suggested that the accumulation of soybean storage proteins, which is enhanced by culturing soybean embryos on high osmotica, is a consequence of elevated ABA content. In B. napus, on the other hand, Finkelstein and Crouch (7) (20).…”

mentioning

confidence: 99%

Effects of Abscisic Acid and High Osmoticum on Storage Protein Gene Expression in Microspore Embryos of Brassica napus

Wilen

Mandel²,

Pharis³

et al. 1990

Plant Physiol.

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“…The resulting cotyledonary haploid embryos can germinate and grow normally to the flowering stage. Embryo-specific accumulations of storage proteins and lipids were also detected in the androgenetic embryos as they were in zygotic embryos (Crouch, 1982;Taylor et al, 1990). In addition, more than 10 4 embryos can easily be obtained from a 10-mL culture.…”

Section: Discussionmentioning

confidence: 94%

Developmental Stage-Specific and Nitrate-Independent Regulation of Nitrate Reductase Gene Expression in Rapeseed

et al. 1996

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cDNA clones for two isogenes of nitrate reductase (NR) have been isolated from rapeseed (Brassica napus 1.) androgenetic haploid embryos induced by microspore culture. NR mRNA accumulation can be detected by northern hybridization at 14 d after culture initiation when embryos develop to the heart/torpedo-shaped stage. Whole-mount in situ hybridization experiments demonstrate that the mRNA accumulation is developmental stage specific. In addition, even when cultured in media containing no nitrate, embryos accumulated NR mRNA to almost the same level as the control. This indicates the unique regulation of NR in embryogenesis in which NR mRNA transcription is activated in a developmental stage-specific manner that is independent of nitrate induction. In zygotic embryogenesis, a stage-specific accumulation of NR mRNA was also observed. By contrast, the obvious effect of nitrate on NR expression that has been reported in many plant species was also confirmed in rapeseed leaf. Quantitative combined reverse transcription-polymerase chain reaction analysis suggests that the flexible and variable regulation of N R expression, which is organ specific, nitrogen metabolite specific, and developmental stage specific, is caused principally by regulation of one major structural gene.NR is a key enzyme in the first step of nitrate assimilation in higher plants (reviewed by Pelsy and Caboche, 1992). The first factor identified that regulates NR activity was nitrate (Tang and Wu, 1957), which strongly induces NR mRNA transcription (Crawford et al., 1986; reviewed by Crawford, 1995). Many other factors such as light, phytohormones, and carbon and nitrogen metabolites and their translocation and intracellular compartmentation also appear to be involved in NR expression (reviewed by Caboche and Rouzé, 1990; Warner and Kleinhofs, 1992; Hoff et al., 1994; Lilo, 1994). However, these studies focused mainly on the phenomena observed in vegetative organs such as leaves and roots. There is little information on nitrate assimilation at the molecular level in developing embryos in higher plants, probably because of the difficulty in sampling embryos in early developmental stages.Recently, we found that Gln is essential for inducing and maintaining androgenetic embryogenesis from isolated microspores in rapeseed (Brassica napus L.) (Ohkawa and Maeda, 1992). Further, it was revealed that whereas Gln was the only nitrogen source to be utilized in the first 4 d 39of the microspore culture, embryos at the multicellular stage could assimilate ammonium salts, and the heart/ torpedo-shaped stage embryo at 14 DAP acquired the ability to use nitrate as the sole nitrogen source (Y. Ohkawa, M. Maeda, H. Fukuoka, and T. Ogawa, unpublished data). The NADH:NR activity, examined in O-, 4-, 8-, and 14-DAP embryos, was detected only in 14-DAP embryos. Since the original culture medium contained nitrate as a nitrogen source, it is possible that NR expression in embryos in the early stages involves nitrate-independent regulatory mechanisms.Here we report ...

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“…Because of their high enzymatic activity, homogenates of immature embryos are able to make TAG. It has been demonstrated that they can synthetize trierucin in the presence of 1,2-dierucylglycerol and erucyl-CoA (Taylor et al, 1990(Taylor et al, , 1991(Taylor et al, , 1992Friedt and Lühs, 1995). The technique of the immature embryos can be used as a method of early sorting, coupled with the one of DHs.…”

Section: Use Of Doubled Haploid Linesmentioning

confidence: 99%

Erucic acid rapeseed: 1. Prospects of improvements

Sanyal

Pinochet

Merrien

et al. 2015

OCL

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-In the current context of boosting production of high erucic acid rapeseed, because of the wide range of its industrial applications, this literature review is designed to provide a general overview of available varieties, current knowledge of plant improvement and paths of developing research to increase competitiveness of varieties with high erucic acid content. A limited market dominated by a few companies, cropping burdens of high erucic acid rapeseed varieties among the majority "00" varieties and the still low erucic acid content in rapeseed, explains the reduced and uncompetitive varietal offers. To improve this situation, new varieties could be developed, thanks to the classical methods of selection and biotechnology.Keywords: Erucic acid / rapeseed / variety / selection / biotechnology Résumé -Colza érucique : partie 1. les pistes d'amélioration. Dans un contexte de relance de la production d'acide érucique, à partir du colza, en raison de ses nombreuses applications industrielles, ce dossier bibliographique a pour objectif de faire le point sur quelques variétés disponibles, les connaissances actuelles en matière d'amélioration des plantes et les pistes de recherche explorées pour améliorer la compétitivité des variétés éruciques. Un marché limité, dominé par quelques sociétés, les contraintes culturales des variétés riches en acide érucique parmi des variétés « 00 » majoritaires et la teneur encore limitée des graines de colza en acide érucique expliquent une offre variétale réduite et peu compétitive. Pour remédier à cette situation, de nouvelles variétés pourraient être développées, grâce aux techniques classiques de sélection et aux biotechnologies.

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Storage-protein regulation and lipid accumulation in microspore embryos of Brassica napus L.

Cited by 97 publications

References 44 publications

Effects of Abscisic Acid and High Osmoticum on Storage Protein Gene Expression in Microspore Embryos of Brassica napus

Effects of Abscisic Acid and High Osmoticum on Storage Protein Gene Expression in Microspore Embryos of Brassica napus

Developmental Stage-Specific and Nitrate-Independent Regulation of Nitrate Reductase Gene Expression in Rapeseed

Erucic acid rapeseed: 1. Prospects of improvements

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